A device that can control the flow rate of air flowing into an engine room, on the basis of opening and closing operations of a shutter mechanism provided in a grille opening part at the front of a vehicle body has been known. A device described in Japanese Patent Application Publication No. 2014-80072 calculates the next necessary idle time on the basis of the last operation time and idle time of a shutter mechanism. Here, in the device described in Japanese Patent Application Publication No. 2014-80072, basically, an operation time of the shutter mechanism is a time between turning on and off of an ignition switch, and an idle time is a time between turning off and on of the ignition switch (see paragraphs 0025 to 0027). When the ignition switch is turned on before the elapse of the calculated next necessary idle time, the device described in Japanese Patent Application Publication No. 2014-80072 does not activate the shutter mechanism until the elapse of the necessary idle time, to thereby suppress heating of a motor that is a drive source of the shutter mechanism.